while len(arr)>0:
    while 0 in arr:
        del arr[0]
    digit = int(statistics.median(arr))
    for x in range(len(arr)-1,-1, -1):
        if(arr[x]==digit):
            if(arr[x]%2==0):
                digit-=2
            else:
                digit-=1
            if(digit<0):
                del arr[x]
            break